WO2001059752A1 - Grand piano action comprising a rotatably mounted hammer roller - Google Patents

Abstract

The invention relates to a grand piano action comprising a hammer jack (4), a repetition lever (5) that is independent therefrom, and a hammer roller (8a), which is arranged on a hammer shank (6). Said hammer roller is located at a customary distance from the hammer jack (4) and is in contact with the repetition lever (5). The grand piano action is characterized in that the hammer roller (8a) is mounted such that it can rotate around the axis thereof. As a result, the exertion of force required for pressing down the key is reduced and playing is made easier.

Description

 WING MECHANISM WITH ROTATING HAMMER ROLL

The invention relates to a wing mechanism with a jack, an independent repeater arm and a hammer roller arranged on a hammer handle, which is in contact with the jack and the repeater arm.

The mechanics of modern wings, i.e. the tongue mechanics are based essentially on the inventions of Bartolomeo Christofori in 1726, John Broadwood in 1777, Robert Stoddart in 1777 (patented for John Gilb in 1786) and Sebastien Erard in 1808 (patented in an improved form in 1821) ). The latter mechanism enables so-called repetition, in which after a key is struck, it is struck again without it having returned completely to its starting position, which allows faster play. The development of the jack mechanics and their current state of affairs are explained in the publications by Ehrlich, "The Piano, A History", Oxford University Press, 2nd edition (1990), and by Palmieri, "Piano Information Guide, An Aid to Research" , Garland Publishing Inc., New York & London, 1989.

The fact that the very old principle of jack mechanics has remained largely unchanged until today and has been adopted by all leading wing manufacturers in the world shows the high technical quality of the system and its usability with musical perfection.

Despite the technically high standard of jack mechanics, it is still not entirely satisfactory. Pressing the button still requires a relatively large amount of force. This leads to less physically strong players and Especially with professional pianists, there is often an overload or even damage to health, such as tendonitis, which has already led to the abandonment of studies or occupation of the person concerned. There are indications that health damage among professional pianists has increased in recent years (Wagner, "Medical problems with instrumentalists", Laaber-Verlag, Laaber (1995), and Altenmüller, "Causes and eures of focal limb dystonia in musicians", ISSTIP-Journal, No. 9 (1998), pages 13-17).

In this context it is also of interest that famous pianists, such as Wladimir Horowitz and Glenn Gould, preferred older instruments with well-played mechanics to avoid this so-called "difficult variety" in order to obtain an easier variety.

In the meantime it has already been possible to measure the effort and even the time course of the force applied when striking piano keys. For this purpose, the publication by Drescher, Parlitz, Thiedemann and Altenmüller, "A new measuring instrument for determining and displaying finger forces on the piano keyboard", EURO PIANO, 39th year April-June 1999, issue 2/99, pages 23-28, pointed. The measurement described there is intended, among other things, to introduce beginners to a power-saving style of play on the one hand, and to optimize the striking technique of trained pianists, on the other hand, so that their effort is more economical.

The hammer roller is a critical design component in terms of the force that a pianist must exert to strike a key of a grand piano. It must first be taken into account that under the term "role" the person skilled in the field of wing mechanics is always immobile Component understands that is accordingly not rotatable. The term "roll" simply came from the external shape of this component, on which a curved surface is desired. The easiest way to achieve this is to manufacture the component in the form of a small cylinder. In practice, the hammer roller has been attached to the hammer handle since the beginnings of jack mechanics up to the present day in such a way that the hammer roller was installed as an immovable, non-rotatable cylinder. This type of use of the hammer roller leads to the fact that when the key is pressed on the repeating arm and on the jack, it is only guided along it in a sliding manner. This sliding contributes significantly to the above-mentioned undesirable high effort when striking. This problem is also addressed, for example, in the publication by Junghanns, "Der Piano- und Flügelbau", Verlag Das Musikinstrument, Frankfurt am Main, 5th edition (1979), page 266, which states:

"In addition to the mechanically correct division of the power and load arms on the mechanism, the type of wing mechanics is related to the position of the jack to the hammer roller. If the position is too upright, the jack will slide slightly and thus produce an easier game, but without any force. If, on the other hand, it is too inclined, the force increases when the key is struck, but the jack will not come out easily and will make itself felt through an unpleasant way of playing. "

Regarding the friction that occurs with this mechanism, the following is stated in this publication, page 269:

"Frictions: The same can be said about the axle friction as with the piano. Of the two superimposed parts with their own pivot points, the friction between the roller (meaning the pivot point of the hammer handle to which the roller is rigidly attached. Note of the inventor) and the repeating arm are clearly noticeable. "

Furthermore, the fixed hammer roller has the inevitable disadvantage that the surface of the fixed hammer roller, which is subject to sliding friction, is subject to wear due to the playing of the wing over time. The surface of these known hammer rollers are generally made of leather. In the case of wings, sliding friction on the surface of the hammer roller often leads to very disturbing noises, e.g. to a squeak, and a difficult game. In the respective concert and tuning service, the application of auxiliary materials such as talcum powder, so-called "dry-lube", or powder made of polytetrafluoroethylene (trade name "Teflon") temporarily reduces sliding friction.

A wing mechanism is known from US-A-5239907 which corresponds to the current state of the art. There is a role provided that is in contact with the repeating leg. From the various drawing figures of the publication, a fastening can be seen for the roll, which obviously does not allow it to be rotated. The publication also contains no other reference to the possible rotatability of the roll.

An older type of wing mechanism is known from DE-630420. According to FIGS. 5 and 6 there, this has a roller or a cam, each made of suede and fastened to the hammer handle. Here, too, there is no indication that the roller should be rotatable. It also follows from the alternative to the roll specified the cam that this was not thought of a rotatable component.

However, rotatable rollers are also reported in the prior art. For example, DE-1163123 relates to a wing mechanism in which the butt is provided with a movable or rotatable roller which moves up and down in a rolling manner on the repeating arm, as specified in claim 3 therein. However, this construction is ineffective in reducing the force required to hit the key. The reason is that the known role only has contact with the repeating leg, but not with the jack. The result is that the roller has no function when the button is pressed. Rather, it only comes into action when the hammer falls back after striking the string.

Finally, a mechanism with a rotatably mounted rubber roller is described in DE-38810. However, this mechanism is not a grand piano, but a vertical piano mechanism. The rotating rubber roller is also not located on the hammer, but at the tip of the jack. Due to this construction, the roller does not reduce the effort required to depress the button, because most of the friction does not arise between the jack and the butt, but between the trigger manikin and the hammer beam.

The invention is therefore based on the object of specifying a grand piano mechanism of the type mentioned at the outset, with the aid of which the force required to depress the key is reduced and the pianist is thus able to play a lighter variety which significantly reduces the risk of damage to health. Another object of the invention is to avoid, by reducing the force required to depress the key, that the surface of the hammer roller must be provided with a lubricant again and again in frequently used wings.

The invention solves these problems by a wing mechanism according to claim 1. The usual distance between the hammer roller and the jack is preferably about 0.2 mm.

In the claims 2 and 3, preferred embodiments of the wing mechanism according to the invention are given.

In the wing mechanism according to the invention, the sliding friction used up to the present time between the repeating leg and the jack as well as the fixed roller is replaced by a roller friction by means of a hammer roller that can be rotated about its own axis.

Surprisingly, despite the more than 270 years of development of the wing mechanism, no wing manufacturer worldwide has yet launched a mechanism in which the fixed roller or a corresponding component (such as the aforementioned cam) has been replaced by a rotatable roller. This is all the more surprising since there was undoubtedly a need from the beginning (e.g. for women, children and adolescents) to keep the effort required to play the piano as low as possible. The present invention satisfies this need in a very simple manner and with great effect, contrary to the longstanding practice in the prior art.

The reduction in the force required to depress the button, which can be achieved by the invention, is from the following table. It gives the measured force values in g for the case of the conventional fixed roller and the case of the rotatable roller according to the invention, and the associated saving in force. In both cases, the same wing mechanism was used with the exception of the roller. The measured values are average values of all keys on a grand piano keyboard from bass to treble.

For each key, the effort was measured for three different phases of the keystroke. The low weight corresponds to the force required to move the hammer upwards. The weight corresponds to the force to hold the button down after the stop. The release weight corresponds to the force required for repeating.

table

Size of force,

9

Type of force Effect of the force Fixed rotating roller Saving of energy

Roll with rotatable

Roll, g /% __

Low weight; Hammer moves 50 40 10/20 'upwards'

Hold the button. 20 25 5/25 after arrival | hit I

Release weight j Repeat 200 150> 50 /> 25

From the table it can be seen that the power saving by the invention is 20 to over 25%, which means a very great advantage.

Another significant advantage of the invention is that existing custom wing mechanics in a very simple and therefore inexpensive manner rotatable hammer roller according to the invention can be converted. Due to the unchanged hammer weight, the dynamic of the stroke from pianissimo to fortissimo is fully preserved. Because of the simple implementation of the invention, the conversion can be carried out not only by wing manufacturers and factories specializing in the production of wing mechanics, but also by manual repairers.

According to the invention, it is preferred to use a hammer roller with a surface made of an elastic material, which reduces the noise of the stop and the rolling of the hammer roller on the repeating leg and the jack. A particularly suitable material for this is a felt material. This has an isotropic structure in the form of strands or tubes, thus ensuring constant stress on the surfaces in contact. A change in the force required for the stop over time is practically impossible, and the use of lubricants on the roller and its counter surface is unnecessary.

The invention not only has the advantage that the effort required for the pianist when playing is significantly less than with known mechanisms. One consequence of this is an expansion of his musical expression. For example, better because it is easier to repeat.

In the context of the invention, a plurality of these can also be used instead of a single rotatable hammer roller.

The invention is explained below with reference to the drawings. Show in it Figure 1 is a schematic side view of a first embodiment of a wing mechanism, as described in the prior art.

Fig. 2 is a photograph of part of a second embodiment of a wing mechanism, as is commercially available and belongs to the prior art;

3a shows a schematic side view of the most important parts of a wing mechanism according to the invention;

3b is an enlarged schematic side view of a rotatable hammer roller in its bracket;

3c shows a schematic side view of the hammer roller according to FIG. 3b, but rotated through 90 ° about the vertical central axis;

4 shows a photograph of part of a wing mechanism similar to FIG. 2, but with the rotatable hammer roller according to the invention; and

5a-5c photographs of the wing mechanism according to FIG. 4 in three different positions of the hammer roller.

In all figures of the present drawing, all features with the same function are also provided with the same reference number.

Fig. 1 shows a schematic side view of a first embodiment of a grand piano mechanism, as is known in printed form from Uchdorf, "Handbuch für Klavierbauer", Wilhelmshaven (1985), page 78. The mechanism has a button 1, a pilot screw 2 protruding upward therefrom, a lifting member 3 lying thereover and also pivotally attached thereto a jack 4 and a repeating leg 5 extending obliquely upwards.

A hammer handle 6 is arranged approximately parallel to the repeating leg 5. On the underside, a non-rotatable hammer roller 8 is fastened by means of a connecting element 7, which rests on the upper side of the repeating leg 5 where the upper end of the jack 4 is at a distance of 0.2 mm from the hammer roller 8 on its underside.

When the key 1 is struck, the jack 4 and the repeater leg 5 are raised via the pilot screw 2 and the lifting member 3. The repeating leg 5 moving upwards presses the hammer roller 8 and thus the hammer handle 6 upwards. Since the repeating arm 5 and the hammer handle 6 are pivoted about different pivot points, it is inevitable that the surface portion of the hammer roller 8, which is in contact with the repeating arm 5, must slide on its surface 5a over a certain length. This sliding movement creates a friction between the repeating leg 5 and the hammer roller 8 and causes the above-mentioned undesirable heavy play of the wing mechanism.

Fig. 2 shows a photograph of part of a second embodiment of a wing mechanism, as it is currently commercially available and belongs to the prior art. From this it can be seen that the hammer roller 8 is fastened to the hammer handle 6 by means of the connecting element 7, which extends into the hammer handle 6 on the one hand and into the hammer roller 8 on the other hand, in a manner which prevents rotation of the hammer roller 8.

3a shows a schematic side view of the most important parts of a wing mechanism according to the invention. Their structure 1 and 2 essentially corresponds to the embodiments of the known mechanism according to FIGS. 1 and 2. According to FIG. 3a, the wing mechanism according to the invention has a jack 4, a repeater arm 5 independent of it and a rotatable hammer roller 8a arranged on a hammer handle 6, which is connected to the repeater arm 5 in Contact is there. As in the known embodiment according to FIG. 2, also in the embodiment according to the invention according to FIG. 3a, the upper free end 4a of the jack 4 projects through an elongate, continuous recess 5b in the repeating leg 5 and is freely movable therein. In the illustrated rest position of the mechanics, the rotatable hammer roller 8a rests on the repeating leg 5. The upper free end 4a of the jack 4 projecting through it is located approximately 0.2 mm below the upper edge of the repeating leg 5.

However, between the known mechanisms in Fig. 1 or 2 and the mechanism according to the invention in Fig. 3a, the essential difference is that the hammer roller 8a is rotatably mounted in the invention. For this purpose, it is rotatably angeo in a bracket 9 which is attached to the hammer handle 6.

3b shows an enlarged schematic side view of the rotatable hammer roller 8a in the holding bracket 9.

3c shows a schematic side view of the hammer roller according to FIG. 3b, but rotated through 90 ° about the vertical central axis.

FIG. 4 is a photograph of part of a wing mechanism similar to FIG. 2, but with the rotatable hammer roller 8a according to the invention instead of the non-rotatable hammer roller 8.

The use of the wing mechanism according to the invention will now be explained with reference to FIGS. 5a to 5c. 5a shows the starting position (rest position) of the mechanics. The rotatable hammer roller 8a rests on the surface 5a of the repeating arm 5 and is spaced approximately 0.2 mm from the upper free end 4a (FIG. 3a) of the jack 4 which is passed through the repeating arm 5. The starting position of the rotatable hammer roller 8a is marked by a pin 10 which is laterally inserted into the felt material of the hammer roller 8a. The hammer handle 6 assumes a position approximately parallel to the repeating leg 5 (sloping to the left).

By pressing the button (not shown), the jack 4 and the repeating leg 5 are raised with the cooperation of the intermediate elements mentioned above (pilot screw, lifting member; not shown). This movement is transmitted to the hammer handle 6 via the rotatable hammer roller 8a.

Fig. 5b shows the position of the mechanics at half gear. That is, the position of the hammer handle 6 is almost horizontal. At the same time, the rotatable hammer roller 8a has performed a small rolling movement (to the left in FIG. 5b) on the repeating arm 5. This can be seen in FIG. 5b from the position of the pin 10 offset to the right relative to its position in FIG. 5a.

Fig. 5c shows the position of the mechanism after the hammer strikes the string. The hammer handle 6 is in a substantially horizontal position. The rotatable hammer roller 8a on the repeating arm 5 has been rolled a further distance (to the left in FIG. 5c), which shows the position of the pin 10 in FIG. 5c in comparison to that in FIG. 5b. In addition, according to FIG. 5c, the jack 4 was rotated within the elongated recess 5b in the repeating leg 5 by the rotatable hammer roller 8a pivoted away (to the right in Fig. 5c) and then protrudes with its upper free end 4a out of the above-mentioned recess 5b. That is, even with this pivoting movement of the jack 4, it rolled off between its upper free end 4a and the rotatable hammer roller 8a.

Overall, the rotatable hammer roller 8a thus executes a rolling movement on counter surfaces of the repeating leg 5 and the jack 4 when the key is struck. In the case of the prior art according to FIGS. 1 and 2, instead of this rolling movement only a sliding movement of the non-rotatable hammer roller 8 is possible, which is necessarily associated with a higher friction. This does not apply to the invention and therefore reduces the effort of the pianist. This means that there is also a lower risk of health damage.

Claims

claims 1. wing mechanism with a jack (4), an independent repeating arm (5) and a hammer roller (6) arranged on a hammer roller (8a), which is opposite the jack (4) at a usual distance and with the repeating arm (5) in Contact is established, characterized in that the hammer roller (8a) is rotatably mounted about its own axis. 2. Wing mechanism according to claim 1, characterized in that the surface of the hammer roller (8a) consists of an elastic material which reduces the noise of the stop and the rolling of the hammer roller (8a) on the repeating leg (5) and the jack (4) , 3. Wing mechanism according to claim 2, characterized in that the surface of the hammer roller (8a) consists of a felt material.